: The broad, long-term objectives of this proposal are to better understand the role of alcohol in general aviation crashes and to improve aviation safety. The specific aims are: I) to develop a linked data system for fatally injured pilots based on two complementary data sources, medical examiner records and the National Transportation Safety Board (NTSB) aviation crash investigation reports; 2) to perform a series of analyses using the linked data system to examine the prevalence of and factors related to alcohol involvement in fatal general aviation crashes; 3) to conduct a case-control study to quantitatively assess the relationship between driving-while-impaired (DWI) history and involvement in fatal and nonfatal general aviation crashes; and 4) to disseminate the results to both scientific and public communities, and make relevant policy recommendations. A major component of the U.S. aviation system, general aviation consists of all civilian, noncommercial flights. General aviation accounts for 93 percent of all aviation crashes and 78 percent of all aviation deaths. Previous research on alcohol and aviation has focused on the various adverse effects of alcohol on pilot performance using an experimental approach. Federal Aviation Regulations require background checks on pilots for DWI history, but the association of DWI history with the risk of involvement in aviation crashes has not been established based on controlled epidemiologic studies. Built on extensive research initiated by a FIRST Award, this proposed project will collect and analyze data from medical examiner records, the NTSB aviation crash investigation reports, and driving records. The role of alcohol in fatal general aviation crashes and its association with crash circumstances and pilot characteristics will be examined in depth for pilots who are fatally injured in Maryland, New Mexico, and North Carolina during 1985 through 2001 (n~ 425). The association of DWI history with the risk of involvement in fatal and nonfatal general aviation crashes will be assessed using a case-control design. Cases (n~ 860) are pilots who reside in these three states and who are involved in general aviation crashes during 1994 through 2001, identified from the NTSB aviation crash investigation reports. Controls (n~ 1,720) wil1 be matched with cases on important confounding variables and selected at random from the Federal Aviation Administration's airmen certification system. Information on DWI history will be ascertained through the state motor vehicle agencies. Results of this project can be used to help develop and evaluate intervention programs for prevention and control of alcohol intoxicated flying.